Yes. Sewage systems bear the brunt of natural and human pollution. Stormwater contains sediments, bacteria, nutrients and metals caused by erosional processes as well as from human activity such as agriculture and industrial processes. It also contain pollutants washed in from streets and lawns. Sewage is also a breeding ground for bacteria and microorganisms that are harmful to human health such as fecal coliform, E. coli, and Cryptosporidium.